This plugin is designed to perform some simple class-based widget framework in wordpress. Using it you can write widget classes (or extend some) in object oriented manner. 
There is a simple widget API, defining basic interfaces and classes. AJAX is core-embedded. After writing your class, you must install it (this is done for the purpose of writing custom database data needed for widget functionality) in order to define widgets of this class. After defining widgets you can place them directly to your page using wordpress shortcodes or special plugin function. You can specify skin (special markup) for each widget placement. You can also define containers (or sidebars) and place widgets into them. Containers are also placed on pages using shortcodes or function call.

Mind3doM RyeBread Widgets

Allows to extend your blog with class-based skinnable ajax-featured widgets, optionally arranged in page areas (containers).

mortenf

Do you want to display your latest tweet on your blog? 
Don’t like the look of other <a href="http://twitter.com/" rel="nofollow ugc">Twitter</a> widgets or feeds?
Try Twitter Bubble.
<h3>License</h3>
Copyright (c) 2009 Morten Høybye Frederiksen <a href="mailto:morten@wasab.dk" rel="nofollow ugc">morten@wasab.dk</a>
Permission to use, copy, modify, and distribute this software for any 
purpose with or without fee is hereby granted, provided that the above 
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES 
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

Twitter Bubble

A sidebar widget showing the latest twitter update in a nice talk bubble, suitable for wide sidebars.

Mind3doM RyeBread Widgets vs Twitter Bubble